Revert "Add Accept-Encoding: br for secure Data Reduction Proxy requests."

components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc
index 057ac1cd51d46d848d35345266581c6dab064632..7f0382e235b503e74ba94d764af4f086d069b65b 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc
@@ -23,10 +23,8 @@
 #include "crypto/random.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/load_flags.h"
-#include "net/http/http_request_headers.h"
 #include "net/proxy/proxy_server.h"
 #include "net/url_request/url_request.h"
-#include "net/url_request/url_request_context.h"
 
 #if defined(USE_GOOGLE_API_KEYS_FOR_AUTH_KEY)
 #include "google_apis/google_api_keys.h"
@@ -39,17 +37,6 @@ std::string FormatOption(const std::string& name, const std::string& value) {
   return name + "=" + value;
 }
 
-bool HasBrotliAcceptEncoding(base::StringPiece accept_encoding_header) {
-  for (base::StringPiece encoding : base::SplitStringPiece(
-           accept_encoding_header, ",", base::TRIM_WHITESPACE,
-           base::SPLIT_WANT_NONEMPTY)) {
-    if (encoding == "br") {
-      return true;
-    }
-  }
-  return false;
-}
-
 }  // namespace
 
 const char kSessionHeaderOption[] = "ps";
@@ -167,24 +154,6 @@ void DataReductionProxyRequestOptions::AddRequestHeader(
   request_headers->SetHeader(kChromeProxyHeader, header_value);
 }
 
-void DataReductionProxyRequestOptions::AddBrotliAcceptEncoding(
-    const net::URLRequest& request,
-    net::HttpRequestHeaders* request_headers) {
-  std::string accept_encoding_header;
-  if (!request.context()->enable_brotli() ||
-      !request_headers->GetHeader(net::HttpRequestHeaders::kAcceptEncoding,
-                                  &accept_encoding_header) ||
-      HasBrotliAcceptEncoding(accept_encoding_header))
-    return;
-  if (accept_encoding_header.empty()) {
-    accept_encoding_header = "br";
-  } else {
-    accept_encoding_header += ", br";
-  }
-  request_headers->SetHeader(net::HttpRequestHeaders::kAcceptEncoding,
-                             accept_encoding_header);
-}
-
 void DataReductionProxyRequestOptions::ComputeCredentials(
     const base::Time& now,
     std::string* session,